LSAT Assumption Secrets

The LSAT asks you for the assumption, but in order to get to the assumption you must fully understand the conclusion and the supporting evidence. In that since, you’re doing all the work of a conclusion question and then some. Don’t just dive into the answers, try to come up with a prephrase based on your understanding of the argument.

This is the final article in a series of lesson articles introducing you to LSAT Assumption Questions. The series includes:

How far does the evidence go? What seems to be missing? The assumption will fall tightly into the same areas that the evidence and conclusion do, otherwise the answer is out of scope.

Sometimes the LSAT tries to distract you with unreasonable evidence. Remember, no matter how absurd the evidence is (e.g., all cats are purple), you have to accept them as true for the purpose of the question. On the other hand, if the assumption is absurd (e.g., JoJo is a cat, therefore JoJo is purple, assuming that all cats are purple), your critique of the logic will usually lead you to the right answer very quickly.

If you’re stuck on a couple of answers, try negating them to see which one breaks the argument down. If the argument fails by negating an answer choice, then you know you’ve got the right answer.

LSAT Practice Assumption Questions, Part II

Try these next sample questions for more practice. The answers and explanations follow on the next page. Take no more than three minutes to answer the following questions (and no cheating by peeking at the answers below before you actually try these).

A real estate agent was explaining to a client why the neighborhood he was considering moving to was a mature neighborhood and would not experience the same appreciation of a newer neighborhood. When a new development is started, the real estate developers offer incentives to try to cover their investment making a new development a relatively better bargain. The neighborhood typically goes through stages of development that include landscaping, new shopping complexes and robust city services. Thus, a mature neighborhood costs more.

The real estate agent is assuming which of the following?

(A) No city services are available in this neighborhood
(B) This neighborhood has not appreciated in the same way other neighborhoods have.
(C) Surrounding neighborhoods have no influence on the rate of appreciation.
(D) Neighborhoods without shopping complexes, landscaping and city services cost less than mature neighborhoods with those features.
(E) Once a neighborhood is “mature,” its value will start to decline.

Now try another:

The Chess Club officers started charging its members a $1.00 entry fee for its weekend tournaments to raise money to build a website. Not a single member complained about the fees and the number of weekend competitors remained the same after six weeks, so the club decided to raise the fee to $2.00.

In raising the fee to $2.00, the Chess Club officers assumed which of the following?

(A) Members did not complain about the fees because they felt it was necessary to have a website.
(B) Since the members didn’t complain about the $1.00 fees, they will not complain about the $2.00 fees.
(C) Doubling the fees to $2.00 will probably make some members complain or stop competing in weekend tournaments.
(D) The increased fees will provide enough revenue to operate the club website.
(E) Doubling the entry fees every six weeks will not cause a drop in the number of competitors.

Now we’ll look at the answer and explanations.

The answer to the first question is (D). The real estate agent uses the example of the mature neighborhood and states the features a mature and more costly neighborhood has above what a newly developed neighborhood typically has. The agent assumes (D), that a neighborhood without those features cost less than those with the stated features. Try the negation — neighborhoods with these features cost less — the argument falls down. If they cost less, then wouldn’t there be more room for appreciation? You may have skipped this choice because it seemed too obvious, but in fact many LSAT answer choices are obvious, particularly when you become adept at apply the TestSherpa method to the questions.

(A) is actually the opposite direction of where the agent is going with the argument. If there are no city services, one of the qualities of a mature neighborhood, then why would this neighborhood be mature?

(B) is out of scope, we know nothing about this neighborhood relative to other neighborhoods other than the agent considers it to be “mature.”

(C) The agent never discusses other neighborhoods, so again, out of scope.

(E) Just because a mature neighborhood doesn’t appreciate as quickly as a new neighborhood (according to this agent) doesn’t mean they depreciate. Out of scope.

Now let’s turn to the second argument and make a paraphrase:

Members didn’t complain about the $1.00 fee (evidence) so the officers decided to raise the fee to $2.00 (conclusion).

How do you form a bridge between “no complaints at $1.00,” to “no complaints at $2.00?” You need to bridge $1.00 to $2.00, something like, “members will feel the same about a $2.00 fee as they did a $1.00 fee.”

The answer (B) matches this most closely, “Since the members didn’t complain about the $1.00 fees, they will not complain about the $2.00 fees.” Try the negation: Members will complain about the $2.00 fees. Then why raise them. The argument doesn’t make sense when you negate (B) so it must be the right answer.

(A) We have no idea why members didn’t complain or what they think about the website. Out of scope.

(C) This is against the spirit of the argument, “Doubling the fees to $2.00 will probably make some members complain or stop competing in weekend tournaments.”. It might happen, but it’s probably not what the officers intend so how could it be the assumption. Try the negation here: Doubling the fees won’t cause any more complaints. Doesn’t that make the officers’ argument even better? It can’t be the answer if the negation makes the argument stronger.

(D) is out of scope. We don’t know what it will take to operate the website, just that this is a step in raising some money to do so.

(E) is so out of scope as to be ludicrous. Doubling the fees once is a long way from doubling them every six weeks.

LSAT Assumption Secrets

Let’s recap our LSAT Assumption Secrets:

The assumption is like a hidden premise. If the premises and conclusion are true, the assumption must also be true.

There are three ways to find an assumption

Look for the red flag — that part of the argument that jumps out at you as incomplete or not fully reasoned.

Build a bridge between the dissimilar parts of the premises and conclusion.

Use the denial test.

Using your intuition and forming a prephrase is the fastest way to the right answer.

If you’re stuck on a couple answer choices, use the denial test. If an answer is the central assumption, it should cause the argument to fail when you negate it.